ISO 12764:2017

Overview

ISO 12764:2017 - "Measurement of fluid flow in closed conduits - Flowrate measurement by means of vortex shedding flowmeters inserted in circular cross‑section conduits running full" - is an international standard that defines the use, selection, installation, operation and calibration of vortex shedding flowmeters (vortex meters) for liquids, gases and steam. It focuses on meters inserted in circular pipes that are running full and on flows that are steady or change only slowly. The document includes a glossary and engineering equations for specifying performance but does not cover insertion‑type vortex meters.

Key topics and technical requirements

• Scope and applicability: Applies only to closed conduits running full and to single‑phase fluids; excludes insertion type devices.
• Principle and components: Describes the vortex shedding principle, bluff body designs, sensors for vortex detection, Strouhal number relationships and meter outputs.
• Performance factors: Discusses Reynolds number range, pressure‑temperature (P‑T) conditions, and other performance‑disturbing influences (swirl, profile, vibration, cavitation).
• Installation & siting: Guidance on straight‑pipe requirements, mating pipe selection, valve positioning, orientation and ensuring full‑pipe condition.
• Calibration & K‑factor: Guidance for determining mean K‑factor, in‑situ calibration procedures, and effects such as period jitter (Annex A).
• Construction & traceability: Typical construction details, material traceability, inspection and certification recommendations.
• Diagnostics & operation: Availability and use of diagnostic functions, start‑up, maintenance, limits of operation and shift of calibration.
• Special considerations: Annex B provides special considerations for steam applications.
• Note: the standard states there is insufficient data to define a universal uncertainty band for vortex meters.

Practical applications

ISO 12764:2017 is relevant for flow measurement of single‑phase liquids, gases and steam in industries such as:

• process and chemical plants
• power generation and steam distribution
• oil & gas and petrochemical systems
• water and wastewater treatment
• HVAC and building services It provides practical guidance for selecting, specifying and applying vortex shedding flowmeters where accurate volumetric flowrate measurement in full, circular pipes is required.

Who should use this standard

• Instrumentation and process engineers specifying flowmeters
• Metrology and calibration laboratories performing K‑factor determinations
• Procurement and quality assurance teams requiring inspection and traceability
• Plant operators and maintenance personnel implementing diagnostics and upkeep
• Regulatory and compliance professionals referencing accepted measurement practice

Related standards

• ISO 4006 (Vocabulary and symbols for measurement of fluid flow in closed conduits)
• ISO/IEC Guide 99 (VIM) - International vocabulary of metrology

Keywords: ISO 12764:2017, vortex shedding flowmeter, vortex meter, flow measurement, closed conduits, K‑factor, Strouhal number, calibration, single‑phase, full‑pipe.